1. Field of the Invention
The present invention pertains generally to the field of electronic digital computers and more particularly relates to a generic method for providing computer access to, and control over, infra-red or other transmission media, via a suitably modified but otherwise standard hand held remote control unit. In the interest of brevity, the following description description refers to such a remote control unit as a "remote". According to this invention, an electronic interface simulates manual switch closures which are `seen` by the processor resident in the remote control so that it will transmit the control sequence corresponding to the selected switch over the transmission medium. When used in conjunction with a `learning` infra-red remote, this gives any standard microcomputer the ability to control a large number of devices which commonly respond to one or more unique infra-red control signals. Common examples of such devices are T.V.'s, V.C.R.'s, and stereo system components, although there are many other application areas in both the home and commercial/industrial environments.
2. State of the Prior Art
Microcomputer installations are now widespread in homes, offices and industry and increasingly are employed for controlling other devices in an intelligent, flexible manner under control of an applications program. One of the major problems encountered in designing and implementing such a microcomputer based control system, is the difficulty of interfacing the computer to the various devices to be controlled. Typically, dedicated wiring between the computer and its sensors and control outputs is required. This wiring is often hard to install, expensive and invariably results in unsightly cables and connectors cluttering up the environment to be controlled. On partial solution to this problem is to use the electrical power wiring of the building to transmit the required control signals, and a number of commercial products are available which utilize this approach. In particular the popular X-10 (Registered Trademark) control system is widely available and provides control over a large number of devices. The drawback with this and other similar systems is that it provides only gross control over devices, since it basically only switches the power supply to the device. Thus, these systems are generally limited to ON/OFF control of A/C powered devices, and in the case of incandescent lights, control over the brightness. With the recent definition of the CEBUS standard, devices may emerge which can respond to more complex commands sent over building wiring; however these devices are still a number of years off, and moreover this does not address the problem of controlling the current generation of devices which do not incorporate a CEBUS interface.
In many existing devices this extended control problem has been addressed by providing an infra-red remote interface giving access to the full range of device functions without requiring the operator to physically move to the device in question. Products are commercially available which provide infra-red send/receive capabilities to a microcomputer. These, however, are dedicated devices which must be connected to the computer in order to operate. There is currently no system which takes the approach of modifying an existing remote control unit in such a manner as to provide computer control while also allowing the remote to be used manually as originally intended by its manufacturer. The purpose of this invention is to provide a generic connection mechanism or interface between device remote control units and a microcomputer, in order to permit manual and computerized remote control while allowing the flexibility of choosing among the wide range of commercially available "learning remotes".